Thermostat for scales.



L. JAENICHEN.

THERMOSTAT FOR SCALES.

ArFucATlon mep fis. 19. |911.

Patented June 26, 1917.

lNvNToR L. IAENIGHEN. THERMOSTAT fos scALEs. Arrucmun msn fzs. le. um. 1,231,026', Patented June 26,1917.

INVENTOR UNITED `sirnrns yrn'rnrnr OFFICE.

LOUIS J AENICHEN, OF DETROIT, MICHIGAN, ASSIGNOR TO THE STANDARD COMPUTING SCALE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

THERMOSTAT FOB. SCALES.

T o all 'whom it may concern.'

Be it known that I,`LOU1sJ AENICiIEN, a citizen of the United States, and residing at Detroit, in the county of Wayne and State of Michigan7 have invented' a new and Improved Thermostat for Scales, of which the following is a specification.

This invention is embodied in scales for grocers and other merchants, ofA thegeneral type shown in the Buckingham Patent Num ber 967,880, dated August 23, 1910, and its object is to provide a. scale of that general type with means to overcome the errors which arise because of the changes in the stiifness of the 1oad-resisting springs due to chan es in temperature. A further object of t is invention is to provide means for changing the leverage between the load receiving mechanism and the weight indicating mechanism to compensate for the variations in the load-resisting mechanism be cause of the changes in temperature.

This invention consists in combination with the levermechanismand the load-re I' so sisting mechanism of a scale, of a baseon which said mechanisms are supported, of a pedestalmountcd on the base, a Weight indicating mechanism supported by said pedestal, a weightindicator actuating rod, and means including 'a thermostat connecting this rod with thc lever mechanism. It further consists in a novel linkage between the end of the main. lever of the scale and the i accompanying drawings and particularly4 of the mechanism connected to the rear rthereof. Fig. 5 is a plan of the rear end weight-indicator actuating rodyand a ther- 4mostat mounted on the rod and-connecting to the main lever adjacent the said linkage for causin the adjacentend' of said rod to swing baciiy and forth relative to said lever and thereby modify the operative lever arm connected to the rod. Itfurther consists in the details of construction shown in the fication of the thermostat. Fig. 4 is a rearV elevation of the main lever ofthe scale of the main lever and a cross section of the Specdcation of Letters Patent.

4tioned above. Vlever 3 has secured to -it thearms 7 and the Patented June 26,' 1917.

Application led February 19, 1917. Serial No. 149,407. i

lower end of lthe weight indicator operating rod. Fig. 6 1s a longitudinal vertical section of the lower end of the thermostat.

the lower end of the weight indicator operating rod to the main lever. Fig. 8 is a section on-the line 8-'8 of Fig. 2. Ei 9 is a section on the linc 9-9 of Fig. 3. ig. 10 is a side elevation of still another construction of thermostat.

Similar reference characters refer to like parts throughout the several views.

' It is well known that in spring'scales on account of the'load-resisting springs becoming' weaker with increasing temperatures the weight indicator will indicate greater weights withhigher temperatures than with lower, unless means are provided to' conif pensate for the weakening of the springs with increasing temperatures. In the present scale this difficulty is overcome by causing the weight-indicating mechanism to travel through equal. distancesin spite of varying temperatures for equal increments of 'lod on the load-resisting spring or springs, notwithstanding the unequal ex-4 pansion of said springs. It will be evident that the type of scale shown in the drawings is .merely an example and that the inven- *ion is'not limited to scales of this particular type.

The construction shown in the drawings has a base l which carries a pedestal 42f on which the main lever 3 is mounted. The secondary lever 4 is mounted intermediate its ends on this main lever and the thrust (Fig. 7 is a plan of the link which connects ondai'y lever yis countcrbalanced by a link 6 connectedv tothe base 1, all as fully eX- i plained in the BuckinghamV patent men; The rear -end of the main small Across bar 8, which carries the ears 9 through whicli extends the pin 10.

Mounted on the base 1` is a pedestal '12 of `any desired type which pedestalcarries the shell 13 in which is rotatable the shaft 14, that carries'the wciglit-iiulicating drum 15, and a small pinion 16. The indications 'on -the'drum may be yread through the glass Windows 17 and 18 at the front and rear of the shell. The vertically movable rod '19 has rack tccth 20 at its upper end engaging the small pinion 16, and its lower end is in the form of the channel shown in Fig. 2,

y 65' 0f the rod having a back 22 and sides 23.v The back 22'isof less length than the channel, the sides 23boing bent together at their lower endsand formed with a hole to receive the pin 25.

As shown in Fig. 5, the upper ends of the 4arms 7 are drilled to receive 'the pins 27 which are held in position by the screws 28. On these pins 27 are mounted the ends of the stirrup 29 whose lower middle portion is bent to U shape and which receivesthe pin 25. The washers 32 are held in osition by the screws 33 to .prevent the pin 25 'from moving endwise out of'itsposition in the stirrup 29. It will therefore be seen that the operating rod 19`for.the weight indicator is supported by the stirrup 29 and is caused to move down to turn the drum as -the rear end of the lever 3 is moved down by a load on the platform 5. In order to cause proper engagement between the rack,

teeth 20 and pinion 16, aguide 35 is mounted on the bar 36 which guide may be positioned, as shown in Fig. 1. As a further factor of safety a smallV weight 37 may be mounted to extend forwardly from the indicator rod 19 and thus serve to hold the rackteeth 20 in engage ent withA the pinion 16. If desired either one ofthese devices may be omitted.

Mounted on the rod 19 and 'engaging the in 10 carried on ,the rear end of the main over. is a thermostat made upof two strips of metal '40 and 41, the latter of steel, or

other material having a low coefiicientof expansion, and the: former a stripof brass or other material having a l'ligher c oeicicnt o`f expansion. In Fig. 2,. this thermostat is shown' secured to the bac'k 22 'of the chanby means fof vthe .screw 43 'thatextends through theslot 44 in the thermostat. This slotpcrmits perfect adjustment yof the thermostat but may be omitted'if. desired. The

will .be connected together their entirelength in any desired manner," electric welding preferred. The lower ends terials are 'separate d,-as Sl] form a. fork. that extends o verthe pinhlO carried by the ears 9 on theroar end .of the main lever .The .'main' lever carries a. pair ofknife edges; 46 which! are engaged own in Fig'. 6, to so means of linksj47 that extend up and connect wi springs- 48. The o eration 'of this scale is as follows. The load) on the'platform 5 causes a depressionl of the rear end .of/the main lever 3 th the main -load-resisting links 47 and springs 48. 'i This downward I movement ofthe' rear end of the main lever 3 'causes the arms 7 thereon-to pushv down the -stirrup 29 and with .fit the loweriend which causes the drum 15 tol nel constituting the lower' end of the rod 19 'v two materials eonstitutingthe thermostatof these two maand is restrained through' .the action of the :turn through distances predetermined for 'the weight placed upon the platform. As the temperature rises the springs 48 become' weaker and the distance through which the main lever 3 swings for equal loads will increase. '.As the temperature increases, the' thermostat bends rearwardly at its lower endrelative tothe lower end'. of the'operating rod 19. As the u per end of the thermostat is rigidly coilected with this operating rod, the result of this rearward movement of the lower end of the thermostat .will be to move the lower end of the operating'lod forwardly, thus-decreasing the lever arm which actuates this indicator-operating rod. IVhen the thermostat is properly pro- ;xportioned the amount of reduction of the "length "of the' lever arm actuating the operating rod will beproportioned to the increase in extension of the springs beca-use of the increase-of temperature, so that the amount of rotation of the drum 15 will be constant for equal weights upon' the platform 5 irrespective o f the temperature.

As shown in Fig.-6, the forward movement of -the lower portion of the stirrup 29 will cause-the pin 25 to rise relative to the arms 7. This compensates for the initial expansion of the\springs 48 due to increased temperature- 'Instead of providingthe thermostat with a fork atits lower end to permit the thermostat to move up and down relative to the pin 10, this connection between the two may be fixed and the thermostat maybe permitted. to move up'and down relative tothe rod. This eonstruction-isl shown in Figs. 3 and 9. In these figures the pins 50. extend across A between the side 23 of the-channel portion of the lower end ofthe rod 19 and the' therlnostat is slidahle up and down between these ins. A hole is formed in the lower end o eachsde 23. The-lower end of the 4thermostat is formed with a. hole 51 through 4which the pin 10 ma)7 e'vtend. -The operation of this thermostat is identical with that just described.

The reason for using the upwardly projectin arms 7 on the mainl leve-r 3- is to provid or long arms of'thestirrup 2Q which will lcause no more vertioalf'inovement of the, -pin 25 thanis necessary'to compensate for theinitial expansion and contraction of: the springs while the middle portion of" .the stirru s swings forward r backward. In 'g.10,the rod 19 is shown to be' flat sided-and to have its lower end bent for: ward -and provided with a hole 55 to rece-ive, the in'25. The thermostat is secured to theboss 56 on this rodfby means of the screw 43 as indicated in Fig. 2.- In all respects the thermostats shown in Figs. 2 and 10 are alike and operate in t-he Vsame manner.

I claim 1. In a oomputin of a base, a lever mounted thereon, a loadlreeei ving platform connected to the lever, a

pedestal mounted on the rear Vendof the base. a shell mounted on the upper end of the pedestal, an indicatin drum revolubly mounted within said shel, a rod longitudinally movable within said pedestal to actuate said drum, a stirrup pivotally connected to the rear end of the lever, a pin connecting the lower end of-said rod to said stirrup, and a thermostat mounted on said rod and engaging said lever to swing the lower end o'f said rod toward the fulcrum-of said lever as the temperature increases and .away from the fulcrum as the temperature decreases. I

2, In a scale,A the comblnatlon of a base, a load-rece1v1ng lever fulcrumed thereon, a

' weight-indicating mechanism, a rod connected to said weight-indicating mechanism, a stirrup pivotallymounted on-the lever,

means to pivotallyconnect said stirrup to saidrod, and athermostat. mounted on said rodan'd engaging said lever and adapted to swing the lower end of the rod toward and from the fulcrum of said lever.

3. In a scale, the combination of abase, a load-receiving lever mounted thereon, a pedestal mounted-on said'base, ,a drum revolubl;7 'mounted on the pedestal, a drum-,actuatm rod movable within said pedestal, a

loa -resisting spring connected to said-lever,

tal, a rod movable to actuate said weight indicatorJ means-pivoted to the lower end of said rod and Vto said lever and adapted to support said rod a 'd move the same up 'and down .with the' ad acent end of said lever,

said lever and having pivots at their upper 4 ends, a stirrup ivotally .mounted at the upper ends of said) arms and having its middle portion suspended downwardly from said pivots, a pivot pinV connecting the lower end of said indicator-operating rod to the middle portion ofsaid stirrup whereby said rod may be caused to move up and` down with the rear end of said lever, a pin mounted on said lever 4below said arms, a thermostat secured to said rod and having a fork at its lower end engaging said last named pin and bymeans of which the lower end of said rod may be swung back and forth from the fulcrum of said lever.

6. In a scale, the combination of a base, a load-receiving lever fulcrumed thereon, a weight-indicating mechanism above said base, a rod connected to said weight indicator, a4 stirrup pivotally connected to said lever and to the lower end of the rod, and

' a thermostat connected-to said rodand consisting of two flat bars normally substantially parallel with the rod and engaging the lever adjacent to said rod. n

su p

7. In a scale, the combination of a base,

a loadsreceiving lever fulc'rumed thereon, a weight-indicating mechanism above said base,1 an' upright rod connected to said weight indicator and being in the form of a channel at its lower end, a stirrulp ivotally connected to said lever and to t e oWer end of the rod, and a thermostat connected to said rod and consisting of two flat bars normally parallel with the rod and engag" ing the lever adjacent to said rod.

Louis JAENICHEN. 

